Studies on Some Viral Diseases of Sweet Potato in Egypt

Generally Viral diseases are considered to be one of the most important problems affecting sweet potato. In general surveyed on sweet potatoes plants in three different locations in 17 fields in Egypt was in average 1.8 to 34.5% at 19216 samples. The most expressed symptoms were mosaic; yellowing and leaf curl with mosaic.We isolated two isolates of SPFMV from two different locations first isolate was SPFMV-Gh from Gharbia and the other isolate was SPFMV-Ka from Kalyoubia governorates. The two isolates were isolates on indicator hosts I.nil and I.setosa and the two indicators showed symptoms mild mosaic and vein clearing and insurance by ELISA. Obtained result indicated that, SPFMV was inoculated mechanically with difficult to test plants when infectious sap was prepared under cool condition.Myzus.persicae and Brevicoryne brassicae were able to transmit SPFMV. Virus diagnosis demonstrated that SPFMV host range was limited to Convolvulacae. ISEM examination of negatively stained partially purified preparations of the virus revealed the presence of flexuous particles ranging from 800-850 nm in diameter.The RT-PCR technique was used to confirm the identification of SPFMV